Assemblies displaying differential negative resistance, such as tunnel diode assemblies, can be used as components in various types of circuits, including, for example, logic circuits, and microwave oscillators. It can therefore be desired to incorporate assemblies displaying differential negative resistance into integrated circuit structures.
Various devices can be characterized in terms of the current passing through the devices relative to the amount of voltage applied to the devices. Some devices, such as, for example, tunnel diodes, will have an operating region in which an ohmic relationship of current as a function of voltage breaks down, and where a tunneling effect begins. A plot of current-versus-voltage for the devices will have a region referred to as the differential negative resistance (DNR) region, characterized by a non-ohmic relationship of current to voltage, and comprising a maximum in current value (typically referred to as a peak current value), and a minimum in current value (typically referred to as a valley current value).
The ratio of the current at the peak to the current at the valley can be utilized as a figure-of-merit for a device displaying differential negative resistance. Higher peak-to-valley ratios are considered to indicate better-quality devices. Presently, the highest peak-to-valley ratios obtained for integrated circuit tunnel diode devices are less than 8. It would be desirable to develop better devices displaying differential negative resistance which can be incorporated into integrated circuits.
It would also be desirable to develop methodology for incorporating such devices into integrated circuit constructions.